This thesis reports on several new and innovative instrumentation developments to
solve some of the problems of brain activity monitoring, particularly SSVEP (Steady
State Visual Evoked Potentials) studies. SSVEP systems generate suitable stimuli and
record the resulting brain biopotentials from scalp electrodes.
The instrumentation is configured as a 'Neuropsychiatric Workstation', supporting up to
136 scalp electrodes. Operating in the SSVEP mode, the Neuropsychiatric Workstation
reported here significantly improves upon the previously reported spatial resolution and
accuracy of maps related to the generated stimuli. These maps allows insights to be
gained into the cognitive workings of the brain.
A significant component of the work reported here covers the development of the multielectrode
EEG measurement modules and the associated techniques for minimising
interference and cross-talk. The techniques for synchronising recordings from all
electrodes with the stimulus, interfacing to a host computer and real-time storage of the
very large amounts of data generated to hard disk, are all reported.
The SSVEP paradigm uses a sinusoidal-modulated visual stimuli. A novel linearised
LED (light emitting diode) head-up display was developed, in addition to more
conventional stimuli, such as the alternating checker-board display, all with sinusoidal
modulation capability over a range of frequencies.
The Neuropsychiatric Workstation described in thesis has been replicated several times
and is in regular use at Brain Sciences Institute (BSI) at Swinburne University of
Technology, and other collaborative research institutes.
| Identifer | oai:union.ndltd.org:ADTP/216572 |
| Date | January 1998 |
| Creators | Simpson, David Gordon Giles, dsimpson@swin.edu.au |
| Publisher | Swinburne University of Technology. |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | http://www.swin.edu.au/), Copyright David Gordon Giles Simpson |
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